Since I have several days off of work... I've been working on my car... I'm putting my 1.6 rockers, lt4 valve springs and valve seals in my car right now... I ordered a spark plug piston stop from summit racing to put the piston at TDC (my crank hub has been off before... it is off by a few degrees). But the POS isn't long enough to stop the piston... i just rotated the damn thing 360* with the piston stop all the way down.

I was wondering, if I get the piston close to TDC. and wait until there is play in the pushrod. If I can spin the pushrod with the rocker on, it should be at tdc, right? So I can take the rocker off, swap everything out, and put it back on and set the valve lash, right?

 

www.shbox.com

 

yeah uuhh checked there before i posted this... it doesn't give me an answer... everything there requires two ppl, or using the arrow.


it's allright though... i got sick of waiting and went at it anyways...

the answer is no

don't ask me how i found out

 

So then why exactly are you using a piston stop if you have read that site? A piston stop doesn't stop the piston at TDC, and you are going to need 2 find TDC.

 

Disconnect your fuel injectors and crank the engine untill it blows air out of the plug hole (with the plug out obviously). Your now at TDC for the cylinder your working on. If you dont have a cylinder leakage tester to force air into the cylinder to keep the valves up I'd get one, you'll need it. If your engine doesn't have high mileage and your valve seals look ok, I'd leave them..just my opinion because theyre a pain to replace with the valves in the head.. you descision on that part though

 

If you don't have an air compressor for the cylinder leakage tester, some people use rope to keep the valves up, but its much harder to get the springs off because the valves drop when your trying to compress the spring.

 

At TDC, the valves shouldn't drop that far.JMHO

 

That just means your on the compression stroke, not that its at TDC...

 

no a piston stop stops it when the piston is at the most top... if you get the degree when it hits the piston stop... then turn the crank 180's until it hits it again... find the average between those two degrees, you have tdc.....

problem is that the piston stop i got from summit doesn't go down far enough for it to hit the piston.

like i said... nevermind... i already flupped it up. i just went off of the pushrods and now my number 3 cylinder valve is about 1/8th of an inch from dropping into the cylinder... hopefully i can find someone with a spark plug adapter so i can shoot some air into it....

my method worked for two cylinders though....

 

Cant you find tdc and then just follow the firing order, turning the crank 1/4 turn at a time? Its been a while but I believe thats how I did it with my '94. Valves would drop just a little and rest on the piston.

Aaron

 

when i did my first two cylinders, the valves were protruding about 1/2 to 3/4 of an inch from the head..... the one i almost just dropped a valve on, the valve stem went down into the head, but isn't in the cylinder yet

 

The one that is almost in the head, is it on top of the piston? Or is it just sitting there? I cant quite remember but I believe if you do it right, it should only drop maybe and inch or less before resting on the piston.

Aaron

 

You want to be on the compression stroke so that both valves are closed. I know you may not be totally at TDC when air blows out of the hole, but youll be close enough to where you can hook up compressed air and turn the crank a bit to get there (if you use that method).

There are various methods to do it, this is the method I choose. But then again I work in a shop with a compressor and have the tools to do it.

 

Not if you watch your valves.

 

like i said... one man team.... couldn't watch my valve and turn the crank at the same time....


good news is my room mate came home from work and he watch the valve until they came up

all better now.